In 1655, two surveyors for Hempstead Town reported that the "east meadow" would be suitable for grazing. The area quickly became a grazing area for cattle and later, in the 18th century, for sheep. The sheep of the East Meadow, NY area provided the country with more than 50% of the United States' wool needs during that time.

During the American Revolutionary War, East Meadow was occupied by British forces when they discovered the vast amounts of livestock herded there, and remained under their control until the end of the war. Two large farms existed in what is now East Meadow: the Barnum farm (Barnum Woods), and the Carman farm. It is rumored that President George Washington spent a night on the Barnum estate during a trip across Long Island in 1790. A toll booth was operated near the Carman homestead on the Hempstead Turnpike.

Another early settlement was located near what is now the intersection of East Meadow Avenue (formerly called Newbridge Avenue; not to be confused with nearby Newbridge Road) and Prospect Avenue.

The community was home to many Gilded Era estates. The old Hoeffner homestead is now the site of veterans memorial park, and East Meadow's Post Office. The Barnum estate was rented by the Hoeffner family in 1914. Part of the old Barnum farm is now the site of Barnum Woods Elementary School, and the main road that passes by the school, Merrick Avenue, was originally called Barnum Avenue. The Oliver and Alva Belmont (formerly Alva Vanderbilt) estate of Brookholt once stretched across several hundred acres on both sides of Front Street to the east of Merrick Avenue.[1]

As of the census of 2010, there were 38,131 people and 12,062 households residing in the CDP. (759.6/km2).

The racial makeup of the CDP was according to the 2010 census, 5.2% African American, 0.1% Native American, 11.6% Asian, 0.04% Pacific Islander, 1.0% from other races, 1.9% from two or more races, 12.2% Hispanic or Latino. Non Hispanic whites were 69.8% of the population.[3] The ancestries of residents of East Meadow are Italian (28.5%), Irish (17.5%), German (11.8%), Polish (8.8%), Russian (5.8%), United States (5.0%).

Of the 12,186 households, 35.8% have children under the age of 18 living with them, 67.2% were married couples living together, 9.0% had a female householder with no husband present, and 20.8% were non-families. 17.9% of all households were made up of individuals, and 11.6% had someone living alone who was 65 years of age or older. The average household size was 2.94, and the average family size was 3.34.

In the CDP the population was spread out with 23.4% under the age of 18, 7.7% from 18 to 24, 30.1% from 25 to 44, 22.6% from 45 to 64, and 16.3% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 98.6 males. For every 100 females age 18 and over, there were 96.5 males.

The median income for a household in the CDP was $67,185, and the median income for a family was $74,691 (these figures had risen to $86,582 and $97,057 respectively as of a 2007 estimate[4]). Males had a median income of $50,325, versus $35,422 for females. The per capita income for the CDP was $27,076. About 2.3% of families and 1.8% of the population were below the poverty line, including 4.1% of those under age 18 and 4.2% of those age 65 or over.

East Meadow's nine public schools are operated by the East Meadow Union Free School District. The district was organized in 1814 under the name "Brushy Plains," and at one time was the third largest school district in New York State. The first school building was on Front Street (where the East Meadow Public Library building stands today).

Front Street School, once located at the corner of Front Street & East Meadow Avenue, burned down and replaced by the East Meadow Public Library.

Prospect Avenue School, once located on the corner of Coakley Street & Prospect Avenue; students now go to Barnum Woods.

Newbridge Road Elementary School, once located on Newbridge Road, between 7th Avenue & Lawn Drive, has been converted to condominiums. The concrete engraving reading "District No. 3 Public School" remains intact on the front of the building, now the Heritage Square apartments.

McCleary Junior High School, previously Meadowbrook Junior High School, was located on Newbridge Road, in the lot adjacent to East Meadow's Wal-Mart. Has been replaced by a housing development.

Salisbury School, building now serves as the district offices and alternative school

^Fischler,Marcelle S. "Nascent Hall of Fame to Welcome First Honorees"., The New York Times, October 15, 2006. Accessed November 26, 2007. "Dee Snider of Stony Brook, the shock-rocker from the 1980s heavy metal band Twisted Sister, known for his defiant metal anthem We're Not Gonna Take It, and Leslie West of the band Mountain, who grew up in East Meadow, Lawrence and Forest Hills, are also being inducted..."